Wet particle-particle interaction are frequently encountered in dense granular flows involving granulation, coating and polymerization. In these complex flows often heterogeneous flow structures are encountered as a consequence of both (effective) fluid-particle and (strongly dissipative) particle-particle interactions. The presence of heterogeneous flow structures has a profound impact on the quality of the gas-solid contact and as a direct consequence thereof on the performance of the process. Moreover, the presence of wet particle surfaces leads to considerable additional challenges (quantification of additional viscous dissipation in thin liquid films) with respect to detailed modeling based on first principles die to the large separation of length scales.
Due to the inherent complexity dense gas-particle flows with strongly dissipative particle-particle encounters, the multi-scale modeling approach offers a powerful tool to study in detail the competition between fluid-particle and particle-particle interactions in the presence of wet surfaces. The idea is essentially that fundamental models, taking into account the relevant details of fluid-particle (DNS models) and particle-particle (Euler-Lagrange Models) interaction, are used to develop closure laws to feed continuum models which can be used to compute the flow structures on a much larger (industrial) scale. In this presentation the multi-scale modeling strategy for dense gas-particle flows with wet particle-particle interaction will be presented together with illustrative computational results. In addition, areas which need substantial further attention will be highlighted such as the extension to poly-disperse non-spherical particles and systems with coupled mass and heat transport.
Particle impact on a flat wall covered with a thin liquid layer: (top: experiment; bottom: simulation using hybrid VOF-IBM method)
Prof. Hans Kuipers graduated in 1985 at the department of Chemical Engineering of the University of Twente. In December of the same year he started with his Ph.D. study at the Reaction Engineering group of University of Twente on detailed micro balance modeling of gas-fluidized beds. In June 1990 he received his Ph.D. degree in Chemical Engineering and was appointed as assistant professor in the Reaction Engineering group headed by Prof. W.P.M. van Swaaij. In 1994 he was appointed as associate professor in the same group. In 1999 he became fulltime professor in Fundamentals of Chemical Reaction Engineering at the University of Twente. From 2006 until 2010 he was Scientific Director of the Institute of Mechanics Processes and Control (IMPACT) at the University of Twente. Since August 2010 he is a fulltime professor at Eindhoven University of Technology and heads the group Multiphase Reactors. He teaches amongst others introductory and advanced courses on transport phenomena and multiphase reactors. His research interests are in the area of multiphase chemical reactors. He participates in the Gravitation Program Multi-scale Catalytic Energy Conversion (MCEC) and acts as program director Process Technology and member of the Executive Board (EB) of the Advanced Research Center (ARC) Chemical Building Blocks Consortium (CBBC).
